Automatic pilot



Oct. 1, 1935. s. D. MITEREFF 2,015,362

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Patented Oct. 1 i935 I UNITED STATES "PATENT OFF-ICE 2,01s,s62. f i AUTOMATIC rino'r Sergei .n. Miterefl, Peter sburg, ye. Application August 18, 1934, 'Serial Not 740,410:

Claims. o1. 244 929 in the fact that they make the speed governors respond to the rate of change plus the rate oi ,the-rate of change of the turbine speed in addition tothe usual manner of response of the govmernors to the extentof change of the turbin speed from its normal desired value.-

i @The present. invention consists essentially in preferred means by which the above mentioned invention can be extended into the field of the automatic steering and piloting of ships, airships,

- airplanes, aerial and water torpedoes, and other movable objects.

The accompanying drawing illustrates these preferred means and:

Fig. 1 is the cross sectional view of the entire device, three of which are required to attain. a complete stability of an airplane,-one for maintaining the lateral stability, another one i or maintaining the longitudinal stability and the third one for maintaining the directional stability- Fig. 2 is the view from the line A-A of the air jet nozzle used in this device,

Fig. 3 is a detail of a standard of position responsi've to tilting of the craft.

' The construction and operation of this automatic piloting and steering device will now be described.

The primary element .of the device consists of the gyroscopic wheel I rotating athigh speed.

The'axle 2, to'which the Wheel I is keyed, is

mounted on conical bearings inside the'ring -3. The lower part of the ring 3 is provided with weights 8. The ring 3 is pivoted by the conical bearings I inside the ring 5. The ring 5 is pivoted by the bearings B in the pedestal supports 1.

The axle 2 carries the air turbine wheel II encased in the casing 12.. The lower part of the casing I2 is supplied with air under pressure through the ducts I3 in the ring 3, the ducts I4 I in the ring 5 and the ducts I5 in the pedestal supports 1. W Air passing through the wheel I I escapes through 'the holes 21 in the casing I2. In this way air under the wheel II not only drives the gy oscope I at a high rotative speed but also supports a large proportion of the weight The main advantage of these improvements lies of air'at the outlet of the compressor I9 ismaintained constant by the relief valve 2 I loaded by the spring 22 and seating against the valve seat 23. g

r The air chamber 20 at the compressors outlet 5 compensates any momentary fluctuations in pressure produced by the cyclical operation of the compressor I9. The compressor I9 is driven by the electric motor 30 through the shaft 28. The

shaft 28 passes through and .drives also the oil 10 the combined effect of the downward force of the weights 8 and the gyroscopic-action of the wheel I, the ring 3 will always maintain a vertical posi- '20 tion and moreover the axis of the ring 3 betweenbearings I4 will always be horizontal. -It follows from this that the axis ofthe ring 5 between the bearings 4-4 also will be kept horizontal regardless of the lateral inclination of the airplane. 25

The axis of the ring 5 between thebearings 67-6 tip of the nozzle I1 is of a very narrow cross sec- 35 7 tion as is shown on Fig. 2. When the airplane is in horizontal lateral position inthe horizontal center line of the nozzle I1 is located on the line between the bearings 4-4, and also on the center line of the spring I0. When there isno air pres- 40 sure, in the nozzle II' the spring I0 presses against the nozzle and closes it tight. The force of the spring I0 pushing on the nozzle I1 is proportional to the distance of the nozzle I] from the end 3| of the spring I0.- Thenozzle II'is su plied .(ith 45 air from the air chamber 28 through the pipe 24 and the needle valve I8. The pressure of air in chamber 20 is considerably higher than the, minimum pressure required to deflect the spring I0 away from the nozzle H, with the result that the 50 rate of air flow through theneedle valve I8 is prac- 'tically constant during the normal operation of the device. The pressure of air in the nozzle I! is much lower; however, than is-the pressurein V the chamber 20, being practically equal to the 68 minimum pressure required to deflect the spring I away from the nozzle In a very minute distance.-

' -It will be seen therefore that the pressure in the the nozzle H from the point 3|. 'tance between the nozzle [1 and the point 3| is by the spring 41.

nozzle |1 varies in proportion to the distance of Since the disproportional to the angle of the lateral inclination of the airplane it follows that the pressure in the nozzle |1 varies as the angle of theiateral inclination of the airplane. The pressure of air in the nozzle I1 is transmitted tothe top of the diaphragm through the pipe 32. The diaphragm 25 is encased in the casing 25 and it bears upon the cup bleeder valve 33. I

The underside of the diaphragm 25 is opento the atmosphere,- communicating with it by means of the duct 34, duct 35, space duct 31 and the outlet pipe 38. The cup bleeder valve'33is covering the duct 40 supplied with oil under pressure by the oil pump 23,.through the pipe 43, duct 42 valve 21 while the pulsations of the oil pressure due to cyclical operation of the pump 23 are eliminated by the accumulator 44 consisting of the cylinder 45 containing the piston 45 loaded The pressure of oil in the duct 42 is consider'-- ably higher than the-minimum pressure required to lift the cup bleeder valve 33 from its seat. Therefore, the ratezof flow of oil through the needle valve 4| is substantially constant and moreover the pressure of oil in the port 48 is proportional to the total downward force acting upon the valve 33. Since the downward force on the valve 33 is generated by the diaphragm 25, the pressure of oil in the port 40 varies in proportion to the variation of the air pressure in the nozzle l1. Since the variation of the pressure in the *0: the airplane from its lateral horizontal position. The oil pressure existing in the port 43 is I transmitted through the duct 48 to the upper side of the piston 13 mounted slidably in one of the four cylinders of the cylinder assembly 5|.

Thedownward force exerted by the oil pressure on the piston 13 is counterbalanced by the compression spring 58 which is located between the piston 13 and the cover 52 of the cylinder assembly 5|.

Since the deformation ofa spring is proportional to the force acting upon it, the distance traversed by the piston 13, in response to the variation of .oil pressure in the port 48, is proportional to the a ar deviation of from its horizontal position.

The piston 13 carries the piston rod 53 projecting through the cover 52 and pivoted to the lever. 54 at the point 55.

For the sake of clarity in arriving at the characteristic of the whole device it is advisable to set down the basic relationships between the function involved in the form of mathematical equations.

Adapting the following notations:

P- the angle formed by the airplane at the moment under consideration with its normal horizontal position.

F1the distance traversed by the point 55 from the position it occupies with the airplane in horizontal' position and as measured at the same moment under consideration.

the airplane eral horizontal position.

It should be pointed out that the value of P and F can be either positive or negative depending whether the airplane is inclined to the left or to the right from the horizontal position.

In view of the previous discussion we may write: 5

. F1=k4P (1) Where k4 is the constant of proportionality depending upon the stiflness of the spring "I, sin of the diaphragm 25, size of the valve 33 and the area of the tip of the nozzle l1.

The piston 13 carries the dash pct 55 inside of which fits slidably the piston 51 suspended by the rod 58 from the'cup bleeder valve 53. The dash pot 55 is provided with the bypass 55. The opening of the bypass 55 is controlled by the needle valve 43 adjustable manually by turning the head 58.

The cup bleeder valve 53 covers the port 62 of the partition 5|. Oil under pressure is supplied go to the port 52 through the duct 53, duct 54 and the needle valve 55. The valve 53 is loaded by the compression spring 53, and also by the force exerted by the piston 51. The difference of oil pressure between thetop and the bottom of the piston 51 is created by the motion of the piston 13 and this difference is proportional therefore to the speed of movement of the piston 13. It

- ment of the piston 13.

Since the distance traversed by the' piston 13 is 35 proportional to the angle of inclination of the airplane, the speed of movement of the piston 13 is proportional to the rate of change of the angle of inclination of the airplane from the horizontal.

Consequently the difference of pressure between the top and the bottom of the piston 51 is also proportional .to the rate of change of'the angle of inclination of the airplane.

Since the oil pressure in the port 52 varies as 4 the total downward pressure acting upon the valve 53, thevariation in the oil pressure in the port 62 is proportional to the rate of change of the angle of inclination of the airplane. The oil pressure in the port 52 is transmitted to the space 5 above the piston 51 through the duct 53 and the duct 55. The piston 51 is mounted slidably in the cylinder of the cylinder assembly-5|. The

oil pressure acting on thel top of the ,piston' 51 is balanced by the compression spring 13? inter- 55 posed betweenthe bottom of the piston 51 and the cover 52.

Since the deformation of a spring is 'propor tional to the force acting upon-it, the distance traversed by the piston 31, in response to the vari- 80' ation of the oil-pressure under the valve 53, is

proportional to the rate of change of the angle 88 pivoted at point 8| to the left hand end of the 65 lever 82.

Designating the distance traversed by the point 7 8| as F2 we maywrite: i

Where:

'Pthe angle formed by the airplane at the moment under consideration with its normal lat- Its-the arbitrary constant of adjustment depending upon the opening of the valve 48.

T-time.

"II-mathematical symbol used in calculus designating an iniinitesimally small increment.

the rate of change of the angle of inclination of the airplane.

The piston 81 carries the dash pct 88 in which fits slidably the piston 88 suspended by'the rod 18 from the cup bleeder valve 1|. Thedash pot 88 is provided with the bypass 88. The opening of the bypass 88 is controlled bythe needle valve proportionto the rate of change, of the oil pressureintheport82..

The oil pressurein the port I4 is" transmitted through-the duct and the duct=11 to the upper side of the piston 88. T I

The piston 88 is mounted'slidably in one of the cylinders of v the cylinder assembly 8|. The force of the oil pressure acting on the top of the piston 88 is balanced by the compression spring 81 interposed between the piston 88 and the cover".

Since the deformation of a springis proportional to,the iorce acting upon it, the distance traversed by the piston 86 is proportional to the variation of the oilfpressure in the port".

The motion of the piston 88 is transmitted by the piston rod 88 to the right hand end of the lever 82, since the rod 88 is connected to the lever 82 by the pin joint 88.

Designating the distance traversedby the point 88 as Fa-"- we may write:

Fa= o s%;

A Where the same notations are used as in the Equations (1) and (2) with the exception that kc is still another arbitrary constant of adjustment depending upon the opening of the needle valve 84. e s It is well to point out also that the expression n dT I means the rate of the rate or change of the angle ot inclination oi-the airplane.

88 attached to the piston 88 and to'- the plate 88.

inder assembly SL; The rod-I88 is fastened to the cover I88 by the shoulders I88 and I8I. The

rod I88 can be rotated by hand by turning the knob 88 at'the upper end 01' the rod I88. The plate 88 is fastened to the rod I 88 by means "or the screw thread. It will be clear from this The piston 88 carries thedash pot I84 "inside of which flts slidably the piston 8.1 suspended by the rod I88 from the top cover I85 0! the cyldescription that the plate. 88 could be moved up anddown by turning'the knob 88.

The dash pot I84 is provided with the bypass 7 I86. The opening of the bypass I88 can be regulated by the needle valve 82 which can be turned by hand by means of the head 88.

Thepiston 88 is providedwith the piston rod 8| which is connected to the left hand side of the lever 54 through the pin joint 84. The spring 85 is made-purposely so long that itstension ispractically constant during the normal operation or the device. The variation of the oil pressure in the port 48 is balanced therefore almost entirely by the resistance of the oilin, the dash pot I84. The-resistanceoi oil in the dash pot I84 is proportional, on the other hand, to the speed of movement of the iston 88.

Designating the distance traversed by the piston 88, in response to variation of oil pressure in the port 48 as F4 we may write:

vious equations, except that he is still another arbitrary constant of adjustment depending upon the openingoi the valve 82. l By multiplying both sides of the Equation (4) by (IT and integrating we get:

. e (o I Where the same notations are used as in the pre- The lever I 88 is located below the levers 54 and 82. The right hand end 8 of the lever I88 is attached to the lever 82 by link I15 while the left hand end III ofthe lever I88 is attached to thelever 54 by the link II4. Due to the fact that the pin joint II2, by which the link 5 is secured to the lever 82, is located between the joints 8| and 88 of the lever 82, the distance traversed by the end 8 oi! the lever I88 is proportional to the algebraic sum of the distance traversed by the piston 61- and the distance traversedby the piston 88. Likewise, due to the fact that the pin joint H8, by which the link 4 is secured to the lever 54, is located between the joints 84 and 55 of the lever 54, 'the distance traversed by the ,end III of the lever I88 is proportional to the algebraic sum of the distance traversed by the piston 88 and the distance traversed by the piston 18.

Below the lever I 88 is located the lever H8. The righthand end I28 01 the lever H8 is connected to the stem-of thecylindrical pilot valve I28, The valve I28 controls the flow of oil 'under pressure supplied through the pipe I88 either to the right or to the left hand sideof the piston I21 sliding in the cylinder I 28. More particularly when the valve I28 is moved downwards from its neutral position, the oil is admitted to the right hand side of the piston I21 and is exhausted from its left'hand side. The piston" I21 moves therefore to the left. It, on the other hand, the valve I28 is moved upwards, the oil is admitted to the left hand side of the piston I21 and is exhausted trom'its right hand side. The piston I21 moves therefore to the right.' The sidewise movement or the. piston I21 is transmitted'as.

avertical movement to the left hand end lfl of the lever 8 through the arrangement consisting of the inclined bar I86, attached to the pistonred I and the rod I88 attached to the point I82 by a pin joint. 8

In order to minimize friction, the rod I88 is provided with the roller I85 at its lowerend.

The rod I33 is moved downwards by the compression spring I34. The adjustment of the ratio' between the distance traversed by the piston I21 and the distance traversed by the left hand and I32 of the lever H9 is accomplished by the screw supports I31 and I 38 fastened by nuts to the support I39 attached to the piston rod I. The

- levers I09 and 9 are connected by the link 8; Since the pin joint 6, by which the link Ill is connected to thelever IDS, is located between the points H and III of the lever I09, the distance traversed by the points II6 and H1 is proportional to the algebraic sum of the distances traversed by the piston 90, piston 19, pistontl and the piston.

Designating the distance traversed by the point H1, in response to the change of the angle of inclination of the airplane from its horizontal position as "Fa we can write:

F5=kaFi+ltoF,-.'+k1oFa+knF4 (6) Where the same notations are used as in previous equations except that ks, 169, km and ion are constants of proportionality depending upon the ratio of the leverage system interconnecting the points 94, 55,. 8| seats 'with the point II1.

Since a very small displacement of the pilot valve I29 from its neutral position results in a violent motion of the operating piston I 21, it is clear that the pilot valve I 29 is practically stationary'during the normal operation of the de- .vice. This being the case, it is evident that a downward or upward movement of the point II! is immediately followed by the proportional downward or upward movement respectively of the point I32. Since the left hand end I32 of the lever H8 is moving in proportion to the distance traversed by the operating piston I21, the

distance traversed by the piston I21 is proportional to the distance traversed .by the'point II1 Designating the distance traversed by the piston I 21, in response to the change of the angle of inclination of the airplane, as Fa" we may write:

Where km is the arbitrary constant of adjustment depending upon the angle formed by the bar I36 with the direction of motion of. the piston I21. As was explained before this angle can be varied at will by'adjusting screws I31 and I33. The left hand end I40 of the 'piston rod MI is connected tothe ailerons of the airplane either directly through the-suitable cables or through the intermediary of the joy-stick, in such a way as to make the movement of the ailerons proportional .to the movement of the operating piston I21. It is not deemed necessary, however,

to show the connection between the point I40 and the ailerons, since it can be easily designed by anyone skilled in the art to fit any particular case.

Designating the angle made by the ailerons with their neutral position, corresponding with the lateral horizontal position of the airplane, as F 70- g Where his is the constant of proportionality dewe may write:

F=k1aFs I (8) pending .upon' the leverage ratio used in transmitting the motion of the piston I21 to the angular motion of the ailerons.-

i Substituting the value of Fit from theEquations ciflcally described, it will be clear to those skilled (7), (6) (5). (3) (2) and (1) into Equation (8) we get: v

Designating the group of constant coeflicientsbefore each of the terms of the right hand side of the Equation (9) as K1, K2. & and K4 we obtain:

The Equation (10) gives the relationship between the angle of inclination of the airplane and the angle or inclination of the ailerons. This equation represents, therefore, the characteristic of this automatic piloting device. I It is not considered necessary ,to present in this speciflcationthe mathematical proof of the takes care of the permanent change of conditionssuch, for instance, as the shifting ,of the load in the airplane, whereas the last three terms of. the

right hand side of the Equation (10) take care of any sudden changes such as occasioned by a sudden gust of wind, for instance.

Mention has not been made yet of some constructional details which. could be very advantageously incorporated in the device.

In order to prevent the possibility of vibratory motion being set in the spring II) by the action of the air jet against it,'the dampening device consisting of, the pot I42 filled with a viscous fluid is used. The end of the spring III is provided with a weight I43 which slides inside the pot I42. The combination of the inertia of the weight I43 and the fluid resistance of the pot I42 reduce considerably the natural period of vibration of the spring III. on the other'hand in order to increase the natural period of resonance of the space in the nozzle I1, the pipe 32 is filled with a liquid such as oil or mercury. In this way the possibility of resonance between the spring III and the space of the nozzle I1 is eliminated.

In order to counterbalance the weight of the spring I0 and the pot I42. the weight I44 is attached to the opposite side of the ring 5. The lateral thrust of the .air Jet. issuing from the nozzle I1 can be counterbalanced by the similar jet acting on the opposite side of the ring 5.

In order to permit the hand operation of the ailerons, whenever such an operation is desirable, the three way plug valves I45 and I46 are installed in the operating cylinder.-

piston I21 with the exhaust space 36 with the result that the piston I 21 oifers no resistance to the movement of the piston I21 by the hand operation of the joy-stick. Even though the application of the device to maintenance of the lateral stability only is spein the art that the device described is equally well applicable to maintenance of the longitudinal as well as the directional stability of an airplane.

f 1: the device is usedior maintaining the longitudinal stability of the airplane the only modification necessary would consist' in turning the gyroscope assembly 90 from the position shown on Fig. 1 so as to make the supports 1 parallel to the short axis 01' the airplane, andalso by attaching the point I" to the elevator rather than to the ailerons.

In order to adapt the device for maintaining thedirectional stability of the airplane the gyroscope assembly should beturned in such a position as to make the axle I'horizontal and to attach the point 140 to the rudder.

The true gyroscopic compass or the earth induction compass can also be used in connection with the device described in this specification.

In order to adapt the device for stabilization of an airplane against the vertical acceleration the gyro-assembly should be omitted and the diaphragm 25 should be made purposely heavy. It will be advisable also to partially suspend the weight or the diaphragm 25 with a spring. It is obvious that in this case theoil pressure under the valve 33 will vary as the vertical acceleration of the point of the plane where the pilot is located, with the result that if the pilot is located near the tip of the wing it would respond both to the roll of the plane as well as to a vertical acceleration of the plane as a whole.

It used for the above specified stabilization the 7,

point I of the pilot should be connected: to either ot-the following three control surfaces:

(1) To the usual set of ailerons through a leverage system permitting a simultaneous upward and'downward movement of ailerons independent of and superimposed upon the opposite-direction movement of ailerons by the lateral stabilizer.

(2) To a special set of ailerons moving in unison and in the same direction.

(3) To the flaps, it the airplane is equipped with them. It should be pointed out thatii' the pilot is located near the tip or the wing, two of the units will be required, one on each wing, and that in this case the point "I40 should be connected to theusual'aileron ofthe respective wing. In this case the two pilots .will take care automaticallyof the roll and the vertical acceleration and no separate lateral stabilizer will be required.

Since the variation of any function whatsoever, such for instance as temperature, speed, level, etc. can be easily converted into proportional variation oi the fluid pressure, it will beclear that by connecting the pipe =32 to this pressure variation and by connecting the point I to a valve, the opening of which ail'ects the function, the device described above can be easily adapted for control-of such a function.

An important practical advantage of the device is that the dash pots I, 56, and 68 are subjected to a pressure considerably higher than the atinospheric with the result that these dash pots will work equally well in a total or partial My invention is not limited, however, to the useoi' gyroscope for this purpose. The alternate device for measuring the inclinationof the airplane is illustrated in .Fig. 3. The'tube It! is filled with a heavy liquid such as mercury, for example. The tube 1 is inclined approximately .45 from the vertical when the airplane is in the horizontal position. The base of the'tube I41 is attached to the pipe 32 described previously. The tube I" is inclined in the directionin which is to stabilize the airplane. 1

. of the airplane is achieved.

It will be clear that as the angle of inclination of the airplane changes the pressure at the base of the tube I41 changes also due to the variation of the length of the vertical column of mercury in the tube I41. The rest of thedevice will re- 5 spend, of course, to the change of pressure in the pipe 32 in the manner described previously with the result that an automatic stabilization It is well to point out that any of the terms 10- in the right hand side of the Equation (10) can be easily eliminated by disconnecting the piston which gives rise to this term-from the leverage system and by providing a fixed support for the end of the lever which is actuated by this piston.

I claim: 1. In a device for automatic piloting of a movable object including a rudder attached to the object, a servo motor actuating said rudder and r a movable means moving in unison with and. in proportion to the variation of the angle of inclination of the object from its normal attitude; an operative connection between said movablemeans and the servo motor consisting of a dash pot surrounded with viscous liquid under pressure; a :5 piston fitting slidably into said dash pot; means for moving the dash pot in relation to the piston in unison with and in proportion to the movement of said movable means; a bypass between the space above and the space below said piston; an adjustable needle valve partially closing said bypass; a port supplied with fluid under pressure; means for varying the pressure in the port in unison with and in proportion to the variation in the difierence of pressure between the space below and the space above the piston generated by the movement of the dash pot in relation to the piston; a pressure responsive movable means acted upon by the pressure in the port, said pressure responsive movable means moving, in response to- 40 the variation of pressure in the port, in unison with and in proportion to the variation of pressure in said port; a second dash pot surrounded with viscous liquid under pressure; a piston fitting slidably into the second dash pot; means for moving the second dash pot in relation to its piston in unison with and in proportion to the movement of the pressure responsive means; a bypass between the space above and the space below the last mentioned piston; an adjustable needle valve partially closing said bypass; a second port supplied with fiuii under pressure; means 'for vary-.

ingthe pressure in the second port in unison with and. in proportion to the variation in the difference of pressure between the space below and the space above the last mentioned piston generated by the movement of the second dash potin relation to said piston; a second pressure'responsive movable means acted upon by the pressure in the second port, said second movable means moving in uni-" son with and in proportion to the variation of pressure in the second port; a movable means arranged to move with a speed proportional to the magnitude of the angle of inclination of the object from its normal attitude and in a direction coincident with the direction of said angle: a leverage system interconnecting the above mentioned four movable means, said leverage system additively combining the movements of each of said four movable-means and an operative con- 7 nection between said leverage system and the servo motor for actuating said servo motor in g unison with and in proportion to said additive combination of the movements of each of the four last mentioned movable means. 7

2. In a device for automatic piloting of a movable object including a rudder attached to the object, a servo motor actuating said rudder and a movable means moving in unison with and in proportion to the variation of the angle of inclination of the object from its normal attitude; an operative connection between said movable means and the servo motor consisting of a resistance for flow of fluid; a supply of fluid for said resistance; means working from and in conjunction with said movable means for forcing fluid through said resistance in a volume coincident with and proportional to the distance traversed by said movable means; a port supplied with fluid under pressure; means for varying pressure in said port in unison with and in proportion to the variation of the pressure difference across said resistance; a pressure responsive movable means acted upon by the pressure in saidport, said means moving, inresponse to the variation of the pressure in the port, in unison with and in proportion to the variation of pressure in the port; a second resistance for flow of fluid; a supply of fluid for said second resistance; means working from and in conjunction with the pressure responsive means for forcing fluid through the second resistance in a volume coincident with and proportional to the distance traversed by the pressure responsive means; a second port supplied with fluid under pressure; means forvarying pressure in the second port in'unison with and in proportion to the variation of the pressure difference across the second resistance; a second pressure responsive ,means acted-upon by the pressure in the second port, said second means moving, in response to the variation of pressure in the second port, in unison and in proportion to the variation of pressure in the second port;- a movable meansarranged to move with a speed proportional to the magnitude of the angle of inclination of the object from its normal attitude and in a direction coincident with the direction of said angle;' means for producing an effect coincident with and 'proportional to the-algebraic sum of the separate means moving in response to the variation of the function in unison with and in proportion to the extent of change of the function from its normal value, meansmoving in response to the variation of the function with a speed proportional to the extent of change of function from its normal value .andin a direction coincident with the direction of the change of function from its normal value, a leverage system efiecting an additive combination of the distances traversed by each of u the two first mentioned means, means for aflect'- ing the variation of the function, and an operthe last mentioned means for actuating the last mentioned means in unison with and in proportion to said additive combination of the distances.

4. In a regulator for maintaining a function at a substantially constant normal value, means moving in response to the variation of the Inction in unison with and in proportion to the extent of change of the function from its normal value, means moving in response to the variation of the function with a speed proportional tothe extent of changenf the function-from its normal value and in a direction coincidentwith the direction of change of the function from its normal value, means moving in unison with and in proportion to the rate of change of the function, a leverage system effecting an additive combination of the distances traversed by each"of the three first a i mentioned means, means for affecting the varia- I tion of the function, and an operative connection between the leverage system and the last mentioned means for actuating the last mentioned means in unison with and in proportion to said 10 additive combination of the distances. I

5. In an automatic regulator for maintaining function at a substantially constant normal value, means moving in response to the variation of the function in unison with and in proportion to the 18 extent of change of the function from its normalvalue, means moving in response to the variation of the function with a speed proportional to the extent of change of the function from its normal value and in a direction coincident with the 20' direction of change of the function from its normal value, means moving in unison with and in proportion to the rate of change of the function, means moving in unison with and in proportion to the rate of the rate of change of the function, 25 a machine elementefiecting an additive combination of the distances traversed by each of the four first mentioned means, means for ailfectingthe variation of the function and an operative connection between said machine element and the 80 last mentioned means for actuating the last mentioned means in unison with and in proportionto said additive combination of the distances.

6. In an automatic regulator for maintaining a function at a substantially constant value, a 85 means for producing the variation in pressure which is indicative of the variation of the function and'comprising, a nozzle, a cantilever spring member abutting to the nozzle and hindering the issue of the fluid from said nozzle, and a means 40 for moving the spring member transversely in relation to the nozzle a distance proportional in magnitude and corresponding in direction to the extent of variation of said function from its normal value.

'7. In an automatic stabilizer for airplanes, a weight, a cup bleeder valve loaded by said weight, a port covered by said valve, a substantially constant supply of fluid for said port, and a pressure responsive control device moving in accordance with the change of pressure in said port resulting from the changing inertia or gravitational force acting upon the weight. I

8. In an automatic stabilizing device, a pressure transformer comprising, a pressure cell acted upon by a primary pressure, a bleeder valve, a port covered by said valve, a substantially constant supply of fluid to said port, a connection between said pressure cell and said bleeder valve for loading said valve with a force proportionalto 00 the force generated by the action of the primary pressure upon said cell and thus producing a secative connection between the leverage system and .ondary pressure in said port, said secondary pressure havinga fixed ratio to the primary pressure.

9. In anautomatic piloting device, a means for f transforming a controlling force into a fluid pres- I sure proportional to said force consisting of a bleeder valve loaded by said force, a port covered by said valve and a substantially constant supply of fluid to said port, said valve being in equilibrium under the action of the controlling force upon it and the force of fluid pressure in said port acting upon the valve in direct opposition to said controlling force. 10. In an automatic stabilizing device for a anaest- V 7 movable object, a tube fllledwith a heavy liquid, said tube and said means,,said operative connecsaid tube being attached tothe object and being' tion comprising a pressure responsive element inclined approximately iorty-five degrees from connected to the base ofsaid tube and actuated the horizontal plane when the object is in its by the pressure variation at the base of said tube 5 desiredposition, said inclination of the tube being resulting from the change in the head of the in the direction in which the object -is to be liquid in said tube-with the variationof the angle stabilized,- a means for affecting the position oi oi inclination of the object.

,the object, andan operativeconnection between V SERGEI D. M1TEREFF. 

